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In this paper, it is determined that learning retention decreases with age and there is a linear rate of decrease. In this study, four male Long-Evans Rats were used. The rats were each trained in 4 different tasks throughout their lifetime, using a food reward as motivation to work. Rats were said to have learned a task at the age when they received the highest accuracy during a task. A regression of learning retention was created for the set of studied rats: Learning Retention = 112.9 \u2014 0.085919 x (Age at End of Task), indicating that learning retention decreases at a linear rate, although rats have different rates of decrease of learning retention. The presence of behavioral training was determined not to have a positive impact on this rate. In behavioral studies, there were statistically significant differences between timid/outgoing and large ball ability between W12 and Z12. Rat W12 had overall better learning retention and also was more compliant, did not resist being picked up and traveled more frequently at high speeds (in the large ball) than Z12. Further potential studies include implanting an electrode into the frontal cortex in order to compare neuro feedback with learning retention, and using human subjects to find the rate of decrease in learning retention. The implication of this study, if also true for human subjects, is that older persons may need enhanced training or additional refresher training in order to retain information that is learned at a later age.
ContributorsSpinrad, Amelia (Author) / Si, Jennie (Thesis director) / Thompson, Patrick (Committee member) / Ma, Weichao (Committee member) / Barrett, The Honors College (Contributor)
Created2014-05
Description
The amphibian pathogen Ambystoma Tigrinum Virus (ATV) has been an important topic of study within the amphibian community since its discovery. ATV threatens many salamander populations across the US, including those in east-central and southeast Arizona. These populations remain at risk since there are no treatments available. In this thesis, a novel method of inactivation is tested to produce a vaccine with the aim of safely eliciting an immune response within the salamander host. This novel form of inactivation has been tested on several human pathogens but has yet to be used on amphibian pathogens. It has the potential to revolutionize our traditional approach to inactivating viruses. After laser treatment, viral plaque assays suggested that inactivated ATV ceased to grow completely, pointing to the possibility of creating a vaccine. Animal challenge trials were conducted with 60 juvenile Ambystoma tigrinum, but surprisingly there was no protective effect from viral inactivation. Further study is needed to clarify why in vitro and in vivo tests of viral inactivation produced contradictory results.
ContributorsVazquez, Luis Ernesto (Author) / Collins, James (Thesis director) / Tsen, Kong-Thon (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Infectious disease in wild animals has historically been a challenge that is difficult to overcome, primarily because isolating a disease outbreak to prevent further transmission in these types of populations is nearly impossible. Wild animals are free to roam, and humans often have limited means of tracking infection in populations. Vaccines and treatments can be formulated but are often somewhat impractical for wild populations because it is not feasible to vaccinate or treat every member in a susceptible community. One such pathogen, Batrochochytrium dendrobatidis (Bd) is infecting amphibian populations around the world to the point where many species are already extinct. Even though finding an effective preventative for the fungal pathogen may not mean that I am able to reach every member in a population, it may mean the difference between extinction and eventual release back into the wild for threatened populations.
In this study I hoped to create an attenuated version of Batrochochytrium dendrobatidis, by using a novel laser technology: SEPHODIS. This laser technology disrupts hydrogen bonds between proteins in the lumen of the cell while simultaneously preserving the membrane and associated proteins on the outside of the cell. This process ultimately affects the pathogenicity of the target but leaves identity markers intact so that the host immune system may recognize the pathogen and create antibodies against it. The laser was ultimately effective at killing Bd fungal cells, and I did observe a significant change in the appearance of the cells. However, samples obtained after exposure to the laser were contaminated and more research is needed to determine if SEPHODIS could be a feasible method for vaccine production.
In this study I hoped to create an attenuated version of Batrochochytrium dendrobatidis, by using a novel laser technology: SEPHODIS. This laser technology disrupts hydrogen bonds between proteins in the lumen of the cell while simultaneously preserving the membrane and associated proteins on the outside of the cell. This process ultimately affects the pathogenicity of the target but leaves identity markers intact so that the host immune system may recognize the pathogen and create antibodies against it. The laser was ultimately effective at killing Bd fungal cells, and I did observe a significant change in the appearance of the cells. However, samples obtained after exposure to the laser were contaminated and more research is needed to determine if SEPHODIS could be a feasible method for vaccine production.
ContributorsRidley, Kylie Madison (Author) / Collins, James (Thesis director) / Tsen, Kong-Thon (Committee member) / Brus, Evan (Committee member) / School of Art (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Osteosarcopenia is a newly formed term that combines the symptoms of osteoporosis and sarcopenia together because of their concurrent appearances in life. They are both age-related, debilitating conditions that affect older adults’ skeleton and musculoskeletal system. Osteoporosis specifically targets the cells of the bone and make them weak and porous. Sarcopenia attacks the skeletal muscles and deteriorates the muscle fibers, decreasing mass and strength. Both diseases put sedentary elders at high risk of sustaining fractures and proneness to fall. The manifestation of one condition typically leads to the other because of their obvious physical attachments as well as their direct chemical crosstalk. The onset of osteosarcopenia is subtle coinciding with age related processes that become greatly exacerbated and accelerated when coupled with chronic inactivity. Thus, a critical intervention for managing the disability associated with osteosarcopenia is physical activity. While some pharmacological treatments or supplements are known to have positive results in stemming further bone loss, regular participation in moderate-intensity exercises is considered the most effective treatment for attenuating further bone and muscle loss.
ContributorsLam, Ellen (Author) / Swan, Pamela (Thesis director) / Johnston, Carol (Committee member) / Department of Information Systems (Contributor) / College of Health Solutions (Contributor) / Watts College of Public Service & Community Solut (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Diabetes mellitus (DM) is a disease characterized by chronically elevated levels of glucose in the bloodstream. Glucose is a form of sugar that is used as fuel by the body’s cells. Blood glucose levels are usually tightly controlled and regulated through a negative feedback system. When this system fails, however, glucose can accumulate in the bloodstream. This system failure typically results from insufficient insulin release due to malfunctioning pancreatic beta cells or the body has developed a resistance to insulin. Excessive glucose accumulation contributes to chronic inflammation and the hardening of blood vessels in the body. This inflammation contributes to a multitude of debilitating health issues such as neuropathy, nephropathy, retinopathy, renal failure, and/or gangrene of the limbs. Additionally, DM is the 7th leading cause of death in the United States and its treatment comes with a significant economic deficit. While there is currently no cure, pharmaceuticals, dietary modification, physical activity, and weight control are the four main approaches for DM intervention and control. These four approaches each operate to regulate glucose using different biological pathways in order to reduce and regulate blood glucose levels. These pathways include improving insulin sensitivity and correcting pancreatic beta cell function. The purpose of this paper will be to provide an overview of type II diabetes mellitus (T2DM) as well as to review the physiological mechanisms involved with glucose control and finally to discuss the use and effectiveness of the main interventional approaches used with the treatment of T2DM: pharmaceuticals, dietary control, physical activity and weight control.
ContributorsWoods, Jessica M (Author) / Swan, Pamela (Thesis director) / Larson, Rachel (Committee member) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Obesity is becoming more prevalent in the United States and is a result of a several of factors, including an individual's genetics, environment, and societal influences. Of the most important, however, when managing weight is the balance between energy expenditure and energy intake. One's total energy expenditure is constituted of four main components: resting metabolic rate (RMR), thermic effect of food, non-exercise thermogenesis, and exercise thermogenesis. The most prominent of these is RMR, which accounts for about 60-70% of an individual's total energy expenditure.
Differences in RMR amongst individuals is dependent on a multitude of variables including height, adiposity, age, body mass, training status, and of most importance, fat-free mass (FFM). Research shows that the greater the body size, the greater the RMR. This positive association between height and body mass with RMR is attributed to more massive organ systems needed in order to meet the greater metabolic demands of a bigger individual. Research also supports that age is negatively associated with RMR. This is mostly due to sarcopenia, or the loss of muscle mass. The most important determinant of RMR, however, is FFM. Unlike body mass, FFM only accounts for metabolically active tissues including muscle, bone, blood, and all organs. Fat-free mass has been reported to account for up to 80% of the variance in RMR. Resistance training is shown to increase FFM, which results in increases in RMR. However, there are several elements to a successful, progressive resistance training protocols that result in increases in muscular strength and hypertrophy. Strength and hypertrophy gains result in a greater oxidative capacity of muscle, and consequentially a greater RMR. The most influential factor in muscular strength and hypertrophic resistance training is intensity. Moderate intensity programs are recommended for the nonathletic adult population for safety purposes. An intensity 4 of about 80% 1 RM is appropriate for increases in FFM. Training protocols lasting at least three months and that incorporate whole-body exercises have the greatest effects on FFM and RMR. Most studies show that increases in FFM of 1-2 kg are necessary increase RMR by about 3-8%. Interestingly, RT can produce similar increases in RMR and FFM in obese and overweight populations in leaner individuals. Implementing resistance training has been shown to be an effective method in managing weight and increasing both RMR and FFM.
Differences in RMR amongst individuals is dependent on a multitude of variables including height, adiposity, age, body mass, training status, and of most importance, fat-free mass (FFM). Research shows that the greater the body size, the greater the RMR. This positive association between height and body mass with RMR is attributed to more massive organ systems needed in order to meet the greater metabolic demands of a bigger individual. Research also supports that age is negatively associated with RMR. This is mostly due to sarcopenia, or the loss of muscle mass. The most important determinant of RMR, however, is FFM. Unlike body mass, FFM only accounts for metabolically active tissues including muscle, bone, blood, and all organs. Fat-free mass has been reported to account for up to 80% of the variance in RMR. Resistance training is shown to increase FFM, which results in increases in RMR. However, there are several elements to a successful, progressive resistance training protocols that result in increases in muscular strength and hypertrophy. Strength and hypertrophy gains result in a greater oxidative capacity of muscle, and consequentially a greater RMR. The most influential factor in muscular strength and hypertrophic resistance training is intensity. Moderate intensity programs are recommended for the nonathletic adult population for safety purposes. An intensity 4 of about 80% 1 RM is appropriate for increases in FFM. Training protocols lasting at least three months and that incorporate whole-body exercises have the greatest effects on FFM and RMR. Most studies show that increases in FFM of 1-2 kg are necessary increase RMR by about 3-8%. Interestingly, RT can produce similar increases in RMR and FFM in obese and overweight populations in leaner individuals. Implementing resistance training has been shown to be an effective method in managing weight and increasing both RMR and FFM.
ContributorsMccreery, Lillianne Marie (Author) / Swan, Pamela (Thesis director) / Nolan, Nicole (Committee member) / School of Nutrition and Health Promotion (Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
Description
The objective of this thesis was to determine whether Zika Virus (ZIKV) can be effectively inactivated by Selective Photonic Disinfection (SEPHODIS) and determine whether key proteins involved in the infection process are preserved, making SEPHODIS a possible source for vaccine development. As of January 2018, there have been 3,720 confirmed cases of Congenital Zika Syndrome in infants, making a Zika Vaccine a high priority (Mitchell, 2018). SEPHODIS is a process that involves prolonged exposure of an object to a pulsing laser which can render it ineffective. Initially, ZIKV was subjected to laser inactivation for 6 hours, then a plaque assay was performed on both laser-treated and control samples. ZIKV was inactivated two-fold? after laser treatment, when compared with control, as indicated by the plaque assay results. Additionally, both samples were submitted to ELISA to evaluate antigenicity with a panel of monoclonal and human sera. As a second control, virus inactivated by formaldehyde (2%) was used. ELISA results showed that antigenicity of some proteins were preserved while others were probably disturbed. However, ELISA results show that ZIKV envelope protein (E-protein), the protein responsible for viral entry into cells, was effectively preserved after laser-treatment, implying that if laser parameters were tweaked to obtain more complete inactivation, then SEPHODIS may be an appropriate source for the development of a vaccine.
ContributorsViafora, Ataiyo Blue (Author) / Johnston, Stephen (Thesis director) / Tsen, Kong-Thon (Committee member) / School of Life Sciences (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Each year the hospitals in the United States dispose of viable medications worth millions of dollars. These facilities are currently forced to do so not because the medications have expired, or are no longer effective, but rather because to re-use any leftover medications would allow for the possibility of spreading disease. Once a medications sterile seal has been broken, any remaining contents of its container are considered potential pathogenic biohazards, and must be disposed of. The main objective of this thesis was to explore a potential alternative to simply discarding these lifesaving and often expensive leftover medications. The ultimate goal of this work is to establish a process by which excess drugs could be safely and effectively purified for re-use, subsequently cutting costs, and enhancing medication availability. Pseudomonas aeruginosa (P.a.) and Staphylococcus aureus (S.a) were cultured for their commonality in healthcare-associated infections (HAI's), and allowed to contaminate medication-like compounds. These bacterially inoculated solutions were meant to mimic the contaminated medications mentioned above and were then treated with a novel, physical means of pathogen inactivation named SElective PHOtonic DISinfection (SEPHODIS). Pathogen load reduction was determined through plate count assays both before and after exposure to the SEPHODIS system. structural preservation of medication was established through the use of infrared spectroscopy. The results of these experiments furthered the confidence of SEPHODIS as an efficient means of pathogen inactivation, while promoting promise of a real-world application in the form of medication purification.
ContributorsKutemeier, Hayden (Author) / Bean, Heather (Thesis director) / Tsen, Kong-Thon (Committee member) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Obesity has developed into a worldwide health problem that is associated with many risks. The elements causing obesity are complex and numerous including behavioral, psychological, and physiological. Traditional methods of weight loss have demonstrated short-lived positive health benefits and minimal long-term weight loss, which has led to the prevalence of bariatric surgery as an answer to long-term weight loss for Class III obesity. Gastric bypass surgery has become especially popular for its numerous benefits including successful weight loss, improvements in obesity-related diseases, and increased lifespan. Bariatric surgery is still not a perfect solution. Negative effects after surgery range from surgical complications and vitamin deficiencies to altered hormonal levels and metabolic rates. Many questions regarding bariatric surgery still remain including the impact of adolescent bariatric surgery, long-term bone effects, and long-term psychosocial and lifestyle components of bariatric patients. Understanding the good, the bad, and several of the remaining questions regarding bariatric surgery, will help health professionals be more appreciative of the complexity of treating their obese patients.
ContributorsStich, Alexandra M. (Author) / Swan, Pamela (Thesis director) / Sebren, Ann (Committee member) / School of International Letters and Cultures (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Weight cycling (WC) is characterized by repeated bouts of weight loss followed by regain. WC has been associated with a number of adverse health consequences and is a risk factor for cardiovascular disease. Body weight regulation is complex. Little is known about why women who intentionally lose weight are so likely to regain their weight back. Humans are motivated by a variety of psychological pressures as well as physiological stimuli that influence eating behaviors and weight control. One of the complex factors that has been shown to predict weight regain, in weight-reduced individuals, is hunger. Ghrelin is a known gastrointestinal hormone that rises during weight loss and is a strong trigger of hunger and increased appetite. Increased ghrelin levels have been associated with disordered eating behaviors and active weight loss. The Three Factor Eating Questionnaire (TFEQ-R18) describes elements that may affect hunger and satiety. These factors are: cognitive restraint (CR, defined as regulating food intake because of weight maintenance), uncontrolled eating (UE, defined as difficulty in regulating eating), and emotional eating (EE, refers to the tendency to eat more than needed because of mood state). Objective: The purpose of this study was to explore the associations of fasting plasma ghrelin with eating behaviors and weight cycling in overweight and obese women. Methods: This is a cross-sectional observation of women aged 20-60 years who completed a Weight and Lifestyle Inventory (WALI) and the TFEQ-R18. Women provided a 12-h fasting blood sample and plasma ghrelin was measured using a commercial radioimmunoassay (ELISA kit Cat# EZGRA-88k). Intra- and inter-assay CVs were 88.4% + 13.8% and 84.4% + 8.4% respectively. Descriptive data were computed and Pearson correlations were assessed adjusting for age and body weight (SPSS, v23). Results: A WC Index (WCI) was computed as number of WC reported x the amount of weight lost per cycle. 61 women (mean age: 39.3 + 11 yr; BMI: 31.4 + 7; WCI: 70 + 60; range = 0 to 253) completed questionnaires. Ghrelin was significantly and negatively correlated to weight (R= -0.25, P = 0.03), BMI (R= -0.32, P = .006), UE (R = -0.29, p = 0.02), and EE (R = -0.29, p = 0.04). Ghrelin was not significantly related to WCI. WCI was not significantly correlated with any TFEQ-18 subscales. Conclusion: In this observational study, lower ghrelin was associated with higher UE and EE. Thus physiological hunger sensations from ghrelin secretion, is not a likely stimulus of eating behavior in these women. There are a host of psychological triggers, such as stress, loneliness, guilt, anger etc. that may enhance eating. Future research will need to explore what psychological triggers influence eating behavior and why obese women are resistant to the powerful physiological hunger cues of ghrelin.
ContributorsHearns, Joan B. (Author) / Swan, Pamela (Thesis director) / Sweazea, Karen (Committee member) / School of Nutrition and Health Promotion (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05